Converts the energy of a 15-minute interval into average demand and evaluates peaks across a series of intervals. A technical tool for orientation — free, no sign-up; the calculation runs only in your browser.
Enter the energy of consecutive 15-minute intervals, for example from a meter or data logger export.
| Interval | Energy [kWh] | Average demand [kW] | Status |
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Got your maximum? See how it relates to your reserved capacity: Reserved capacity utilisation →
Interval data can show which equipment creates the peaks and when — and whether it makes sense to address them through operations, control or an investment.
It is not an instantaneous peak lasting milliseconds, nor the highest value a clamp meter shows for a moment. 15-minute demand is the average power over a 15-minute interval — the energy drawn in the interval divided by its length.
Example: 5 kWh consumed over 15 minutes means 5 / 0.25 = 20 kW of average demand.
The meter records the energy of each interval, and power is derived from it:
P_avg = E / t t = 15 min = 0.25 h P_15 [kW] = E_15 [kWh] / 0.25 = 4 × E_15 [kWh]
A short inrush is spread out in the 15-minute average. Loads that run together for longer show up in it in full.
Short periods when several loads run together can create peak demand even when total monthly consumption is not extreme. Typically these are:
A monthly bill shows the total energy, not when or why a peak occurred. For that you need interval data.
A single maximum on its own is not enough to design:
That needs interval data over a longer period and the operating context — what was running at the time, and why.
Metering, consumption and peak analysis, and a technical assessment of the next steps: Energy →
This calculation is a technical tool for orientation. It is not a distribution operator's billing calculation, a legal interpretation of a tariff, an energy audit or a BESS or PV design, and it is not a guaranteed basis for changing a contracted capacity. An exact assessment depends on the metering data, the distribution tariff, the type of supply point and the operating pattern; how demand is measured and evaluated can differ between operators and countries.